Dicamba in Canada - 2017

Dicamba on SoybeansStewardship and Sprayer Settings

Dr. Jason Deveau ● OMAFRA Application Technology Specialist ● 2017

This is really two related talks…


Dicambadrift

potential


Dicambadrift

potential

How to spray

Dicamba (per

label)

Is Dicamba drift

unique?

• Particle drift: pesticide droplets or particles moving outside the area treated.

• Particle drift: pesticide droplets or particles moving outside the area treated.• Scale of tens-of-metres.

• Particle drift: pesticide droplets or particles moving outside the area treated.• Scale of tens-of-metres.• Function of sprayer /

weather.


weather.

• Vapour drift: pesticide vapours moving outside the area being treated.


weather.

• Vapour drift: pesticide vapours moving outside the area being treated. • Scale of kilometres.


weather.

• Vapour drift: pesticide vapours moving outside the area being treated. • Scale of kilometres.• Function of chemistry /

weather.

To explain dicamba drift, we need a little history.

To explain dicamba drift, we need a little history.

Let’s set the WABAC to

Dicamba as Dimethylalamine (DMA) Salt Reg. ~1967

BanvellHerbicide

Dicamba as Diglycoalamine (DGA) Salt Reg. ~1983Banvell II

Herbicide


BanvellHerbicide

feXapan

Dicamba as DGAFormulation with VaporGrip (Xtend Reg. 2016, feXapan Reg. tbd)


Herbicide


BanvellHerbicide

feXapan

Dicamba as DGAFormulation with VaporGrip (Xtend Reg. 2016, feXapan Reg. tbd)


Herbicide

Dicamba as N, N-Bis-(aminopropyl) methylamine(BAPMA) Salt Reg. 2016


BanvellHerbicide

• So, Xtend is a new formulation: Banvel II “encapsulated” in a polybasic polymer to further bind the salt and reduce volatility.


• Engenia is a new chemistry: Banvel III, where molecule is “anchored” to a longer salt to reduce volatility.


• Engenia is a new chemistry: Banvel III, where molecule is “anchored” to a longer salt to reduce volatility.

• And we’re still learning what that means to drift potential…

Monsanto’s Physical Drift Tests

• Soybean field in Texas


• Soybean field in Texas• 2 passes at low rate


• Soybean field in Texas• 2 passes at low rate• TTI 03’s & 04’s at 60 psi


• Soybean field in Texas• 2 passes at low rate• TTI 03’s & 04’s at 60 psi • Collection discs placed

downwind – dicamba detected 53 ft away.


• Soybean field in Texas• 2 passes at low rate• TTI 03’s & 04’s at 60 psi • Collection discs placed

downwind – dicamba detected 53 ft away.

• USA doubled that distance to get their low-rate buffer zone.

(53 ft x 2 is ≈110 ft)


Is Volatility an Issue?

Source: Dr. Kevin Bradley, University of Missouri

Is Volatility an Issue?

70% less volatile than DGA

Monsanto’s Volatility Tests

• Monsanto performed tests (no external validation).

• Applied field rate soil in Humadome.• Aspirated at 2 L/min. for 24 hr.

• Rinsed “puff” (polyurethane foam) in ethanol.• Dicamba captured for gas chromatography.

Monsanto’s Volatility Tests

• 32 soybeans in Hoophouse trials.

Monsanto’s Volatility Tests(not pictured)

• 32 soybeans in Hoophouse trials.• Petri plates placed among

plants.


• 32 soybeans in Hoophouse trials.• Petri plates placed among

plants.• Checked for vapour damage

symptoms over 14 days.


What could Dicamba drift do?

Let’s look at the recent dicamba drift issue in the Southern US

http://agriculture.mo.gov/

• In 2016, US planted hundreds of thousands of acres of cotton and soybean with dicamba-tolerant trait.


• However, new low-volatility dicamba herbicides were not yet approved by the EPA.


• However, new low-volatility dicamba herbicides were not yet approved by the EPA.

• Onslaught of herbicide-resistant weeds led some to spray older, off-label dicamba chemistries (poorly).

>200 complaints of dicamba drift filed in AR, MS, MO & TN as of

Oct. 25.

>200 complaints of dicamba drift filed in AR, MS, MO & TN as of

Oct. 25.

Other states were affected, too.

Arguably, Missouri and Arkansas have been impacted most…

Number of official pesticide complaints (ag. & non-ag. use)

investigated by Missouri Pesticide Program:

Source: Missouri Department of Agriculture



2011: 97




2011: 97 2012: 75 (1 dicamba related)




2011: 97 2012: 75 (1 dicamba related) 2013: 75




2011: 97 2012: 75 (1 dicamba related) 2013: 75 2014: 90 (3 dicamba-related)




2011: 97 2012: 75 (1 dicamba related) 2013: 75 2014: 90 (3 dicamba-related) 2015: 97 (27 alleged dicamba-

related)





related) 2016 (Jun22-Aug25): 98 (92 alleged dicamba-related)







Alleged drift damage to >41,000 acres of soybeans, peaches, tomatoes, watermelons, cantaloupe, rice, purple-hull peas, peanuts,

cotton, alfalfa, residential gardens, trees and shrubs.






Alleged drift damage to >41,000 acres of soybeans, peaches, tomatoes, watermelons, cantaloupe, rice, purple-hull peas, peanuts,

cotton, alfalfa, residential gardens, trees and shrubs.

UPDATE (Jan 7, 2017))

U of Missouri’s Dr. Kevin Bradley (@showmeweeds) at SWAC in Jan.:


• ~80% of Missouri’s ac. have a 3- or 4-way resistant weed.



• He’s walked all 120 “official” cases and many more “unofficial”.




• >100,000 ac of burned soybean, alone (60% clearly physical drift).





• Some night-sprayed, 2 or 3x same field at 2-3x DMA or DGA label rate.





• Some night-sprayed, 2 or 3x same field at 2-3x DMA or DGA label rate.

• One soybean applicator burned 20 neighbours…

• Tragically, Arkansas farmer Mike Wallace confronted a neighbour about dicamba damage to 40% of his soybeans, and was shot to death. (Oct.)

Arkansas

• Federal warrants issued in Arkansas for EPA Criminal Investigation into misuse of dicamba (Oct.)


• State Plant Board recommended increasing the fines for misapplication from $1,000 per violation to $25,000 (Nov.)


• State Plant Board recommended increasing the fines for misapplication from $1,000 per violation to $25,000 (Nov.)

• They proposed MANDATORY training requirement for all applicators using the new auxin technologies.

(On Jan. 4, governor supported proposals. NC state already enforces mandatory training.)

• As of Feb. 13, 2017, Mississippi State University Extension started offering free, self-paced online training:

http://www.auxintraining.com/


www.auxintraining.com





• University of Arkansas Cooperative Extension now has a program, too.





• University of Arkansas Cooperative Extension now has a program, too.

• Be aware: Some US restrictions differ from CA.


• So, even if you have access to other dicamba options (e.g. generics), use

the new low-volatility products.

$27.40/litre (MSRP)

$6.85/ac (250 ml/ac)



MSRP ($CDN) for lowest rate of dicamba products on soybean

$27.40/litre (MSRP)

$6.85/ac (250 ml/ac)

$18.50/litre(MSRP)

$6.10/ac (333 ml/ac)




$27.40/litre (MSRP)

$6.85/ac (250 ml/ac)

$18.50/litre(MSRP)

$6.10/ac (333 ml/ac)




$33.37/litre(MSRP)

$6.48/ac (194 ml/ac)

$27.40/litre (MSRP)

$6.85/ac (250 ml/ac)

$18.50/litre(MSRP)

$6.10/ac (333 ml/ac)




NoLonger

available

$33.37/litre(MSRP)

$6.48/ac (194 ml/ac)

In GA, no “official” off-label dicamba drift complaints! But

Why?

• Est. 648,000 acres (i.e. half) of Georgia’s cotton crop was planted with Xtend cotton.


• Since winter, 2015, 1,499 Georgia growers (2,114 total) took “Using Pesticides Wisely” training course.


• Since winter, 2015, 1,499 Georgia growers (2,114 total) took “Using Pesticides Wisely” training course.

• Perhaps informed growers made better choices…

What do the Dicamba

labels say?

The labels have been built over time.

• >30 year old Banvel II label for corn and cereals.


• Monsanto develops Xtend trait for soybeans and drafts dicamba use.



• BASF & Monsanto collaborate to ensure label consistency.




• Soybean section added to BASF’s Banvel II & Monsanto’s M1691 labels.





• This formed the basis for XtendiMax and Engenia labels.






• XtendiMax registered, but label changes needed.







• Engenia registered with those label changes.







• Engenia registered with those label changes.

• Changes to XtendiMax label forthcoming...

• No AMS (Ammonium Sulfate)


• 110 ft (33 m) downwind buffer for low rate



• TTI 03-04 @ 50-60 psi*



• TTI 03-04 @ 50-60 psi*• ≤20 in (50 cm) boom

height



• TTI 03-04 @ 50-60 psi*• ≤20 in (50 cm) boom

height• No tank mixing**Tips and tank mix partners are undergoing

testing to prove they do not adversely affect offsite movement potential.

• www.xtendimaxapplicationrequirements.com• www.fexapanapplicationrequirements.dupont.co

m

Bryan Young (Purdue University ):

Mixing order for the new dicamba formulations shouldn't differ from what spray applicators are accustom to with other herbicides. "The main thing is timing. Spray small

weeds and use the most restrictive label for weed size or crop growth stage."

FeXapan

How do I spray

Dicamba?

ASABE 572.1 is a standard that defines categories for flat fan spray

quality based on the droplet size range, & number relative to volume.

Most nozzle manufacturers voluntarily comply with 572.1

and provide spray quality information.

Most nozzle manufacturers voluntarily comply with 572.1

and provide spray quality information.

• Stats humour.

• A single nozzle produces a range of droplet sizes.


• The median droplet size changes with pressure.


• Rate controllers adjust pressure according to travel speed.

• The median droplet size changes with pressure.

Make your pressure gauge your speedometer (Dr. Tom Wolf)


• Operate nozzle from mid-to-high pressure range.



• Allows you to slow without compromising uniformity.



• Allows you to slow without compromising uniformity.

• But you must ensure XC-UC spray quality… so you have to read the nozzle tables!

In Canada, Spray quality is BLACK & WHITE


• Agrifac’s HTA D3-21 TKSS-5 liquid/ air nozzle: XC 30-87 psi, 0.23-0.45 US g./min.

• Wilger’s Combo-Jet UR110 series• John Deere’s PSULDQ series

(2004’s?)• Greenleaf’s D-Series


Nozzle choices improving in US (Mar. 1st)

Nozzle choices improving in US (Mar. 1st)

But are they really useful?

Slower travel speeds allow lower booms


• It’s 50 cm from target, max.


• It’s 50 cm from target, max.• Low booms reduce physical drift

and improve coverage.


• It’s 50 cm from target, max.• Low booms reduce physical drift

and improve coverage.• Efficiency gains from faster fill /

clean times, even when driving slower.

When do I spray

Dicamba?

• Timing matters!

• Timing matters!

• Single, high rate, 1st pass?

Length of Residual Control(per Mike Cowbrough)


• Low Rate (300 g ae/ha)~ 2 weeks


• Low Rate (300 g ae/ha)~ 2 weeks

• High Rate (600 g ae/ha)~ 4 weeks(Mike figures 2-4 depending on conditions)

I understand wind, but what’s an Inversion?

Temperature inversion



• Temperature inversions supress thermal turbulence, and concentrated spray-laden air flows laterally.


• Temperature inversions supress thermal turbulence, and concentrated spray-laden air flows laterally.

• Moves either downhill (like water) or with light breezes.

When do inversions occur?

When do inversions occur?• Inversions, once formed, persist

until the sun rises and warms the Earth’s surface, or until winds increase and mix the stationary “layers” of air together.

When do inversions occur?• Inversions, once formed, persist

until the sun rises and warms the Earth’s surface, or until winds increase and mix the stationary “layers” of air together.

• At sunrise, the inversion will be at its maximum height.

Inversion intensity varies

•Humidity slows the formation and reduces the intensity of an inversion.



•Cloud cover bounces long wave radiation back to Earth, making it warmer and reducing inversion intensity.



•Cloud cover bounces long wave radiation back to Earth, making it warmer and reducing inversion intensity.

•Wind (>6 or 8 km/h) stirs the air vertically, reducing inversion intensity.


Any other way it

might move between fields?

• Here are serial dilution rinses, sprayed on conventional soybeans

Photo source Monsanto demo plots: Chatham, Ontario






What did you spray before and after

dicamba?

•Dicamba (by design) binds to clay particles.


dicamba?

•Dicamba (by design) binds to clay particles.•Atrazine is hard to clean out.


dicamba?

•Dicamba (by design) binds to clay particles.•Atrazine is hard to clean out.•Even after multiple tanks, dicamba bound to Atrazine (or any DF or WDG formulation) can break loose from filters and wreak havoc.


dicamba?

• ~1 cup of spray solution in a 1,200 gal. tank = significant foliar injury to conventional soybean, but not necessarily yield loss.


• 1 to 2 gallons of spray solution in a 1,200 gal. tank = significant yield loss to conventional soybean. Dr. Kevin Bradley, University of Missouri


• 1 to 2 gallons of spray solution in a 1,200 gal. tank = significant yield loss to conventional soybean.

• Flowering soybean exposed to dicamba particle drift (~1/100x use rate) will experience an approximate 9% yield loss.

Franklin et al. (2014) Weed Science 62: 193-206.

Dr. Kevin Bradley, University of Missouri

Flag the Technology (2011)

• Color-coded bicycle flags on field corners indicate herbicide tolerance for spray planes.


• Color-coded bicycle flags on field corners indicate herbicide tolerance for spray planes.

• Saved a lot of trouble in AR, MI, MO and LA.


Glyphosate resistant weed control(per Mike Cowbrough)

Waterhemp

NO: Better options exist

Giant ragweed

YES: Pre-plant(May also need POST)

Common ragweed

YES: Two-pass (PP/PRE fb POST)

Canada fleabane

YES: Pre-plant(May also need POST)

Dr. Dan Reynolds >30 years as an Extension & Research Weed Scientist

Mississippi State University

“If there’s any doubt,

don’t pull the trigger.

If there’s any doubt in

your mind, don’t spray.”

Tom Wolf@nozzle_guy

Jason Deveau@spray_guy

Learn more about spraying

www.sprayers101.com

Education

Dicamba in Canada - 2017